Reversible counter



July 2, 1968 H. L.. sElDEN REVERSIBLE COUNTER I 2 Sheets-Sheet 1 Filed April 4, 1966 K IN-VENTOR. e/m/f/ae/n l l JrfaxEA/En July 2,1968 y y H; L, sElpEN 3,390,834

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United States Patent 3,390,834 REVERSIBLE COUNTER Herman L. Seiden, Chicago, Ill., assigner to Lion Manufactoring Corporation, Chicago, Ill., a corporation of Illinois Filed Apr. 4, 1966, Ser. No. 539,919 10 Claims. (Cl. 23S- 91) The invention relates to counting mechanism of the known type having a series of coaxial, side-by-side num-ber wheels each bearing digits numbering from zero to nine for counting units, tens, hundreds and so-on, with tenstransfer mechanism between successive wheels for consecutive counting from zero up to the capacity of the particular wheel assembly involved. Such counters are commonly actuated by a pawl and ratchet drive which may be driven mechanically or electromagnetically from any source of counting pulses, the disclosed counter being reversely driven by a pair of electromagnets, respectively energizable for additive or subtractive stepping of the counting wheels in consequence of correspondingly reverse oscillations of a stepping pawl of an especially contrived configuration cooperatively wit-h certain novel armature constructions.

'Among the features of novelty and utility inhering in the construction described hereinafter are: the provision of a single lightweight, one-piece reverse-acting drive pawl, and an armature means for oscillating the same to impart add and subtract movements to the counting wheels; the provision of simplied means for pivotally and removably mounting the armature on a flat casing Wall; the provision of a single, spring-urged rockable means for centering the armature and imparting a snapaction thereto without loading the same unduly, in order to hold the armature in its oppositely-attracted positions relative to the electromagnets; the provision of a simple off-zero switch-actuating mechanism cooperable with all counting wheels and effective to actuate a signal switch in one condition when the wheels are all in the zero position, and in another condition whenever the Wheels indicate a count ot-her than zero.

Still further aspects of novelty and utility characterizing the counter mechanism relate to details of the construction and assembly of the component parts and the encasement for the mechanism as separable subassemblies; a manual actuating means, and other features of construction and operation all of which will appear more particularly hereinafter in view of the annexed drawings, in which:

FIGURE 1 is an elevational view of the counting wheel and pawl subassembly;

FIGURE 2 is an inside elevational view of the driving pawl and wheel index means as Seen along lines 2-2 of FIGURE 1;

FIGURE 2A is a change-position detail showing the pawl of FIGURE 2 in neutral position;

FIGURE 2B depicts a modified form of drive p-awl for unidirectional drive of the counting wheels;

FIGURE 3 is a perspective view showing parts seen in FIGURES 1 and 2;

FIGURE 4 is a side elevation of the drive magnet casing and subassembly;

FIGURE 5 is a view looking inwardly of the drive magnet casing along lines 5-'5 of FIGURE 4;

FIGURE 6 is a view of the magnet subassembly looking downwardly along lines 6-6 of FIGURE 4;

FIGURE 7 is a rear elevation of the casing structure yseen in FIGURES 4 to 6;

FIGURE 8 is a perspective view of the assembled counting unit;

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FIGURE 9 is a perspective detail of the drive pawl, driving armature, and centering blade.

'Referring to FIGURE =l, the counter includes as a part of a wheel subassembly, a set of counting wheels 10 of known construction (except as modified for purposes hereinafter set out) for cumulative or additive counting of units, tens, hundreds and thousands, according to the embodiment shown for illustrative purposes, in digital increments, as a result of stepping or driving pulses applied to the first -or units-counting wheel indicated at 10A, andthe action, as necessary, of the usual intercoupling tens-transfer gear teeth (not seen) located on the sides of the wheels in such manner that following the ninth advance of a preceding counting wheel, the next higher value wheel `will be automatically coupled for one step or digital movement, -all in a manner well-understood in the art and not of itself forming a part of the present improvements.

-The counting wheels are mounted on a common shaft 11 seated between opposite wall portions .14 and 16 of a formed plate serving as the chassis for the counting wheel subassembly (see FIGURE 3 also) which interfits with a complementary subassembly chassis generally indicated at 17 in FIGURES 4 to 7 and completes a closed housing such as seen in 4FIGURE `8.

The numbers on the several counting wheels are visible through an elongated sight-opening 19 in the top wall 15 of lthe wheel subassembly chassis, FIGURES 1 to 3.

Both the counting advance and subtractive or retrogressive movements of the wheel -10 are achieved by an oscillable stepping pawl 20 of novel configuration, which is pivoted at 21 on the wall portion 14 of the wheel chassis, FIGURES 2 and 3.

The pawl 20 is desirably formed of a light material such as aluminum having a plurality of holes formed therein to further reduce the mass, along with a coupling 23 of hour-glass Shape, and an especially-contrived arcuate gear slot 25 which freely fits over a trident drive gear 26 forming a part of the first idler tenstransfer gear 12A which is one of a set of such gears on the shaft 13 and having driving engagement with the sidewise gear teeth 10AX on the first or units counting wheel, FIGURE l.

A centralized salient tooth formation 27 and an oppositely-recessed tooth formation 28 in the arcuate gear slot 25 provide two sets of oppositely offset drive teeth 27X and 28X, and 27Y and 28Y located on opposite sides (right and left, FIGURES 2, 2A) of the central salient tooth.

The offset upper and lower pawl teeth in each said set are so spaced radially and angularly relative to each other as to engage one of the trio of teeth 26A, 26B, 26C on the tri-dent drive gear whenever the pawl rocks one Way or the other from its normally centralized or neutral position of rest, as from the position of FIGURE 2A to that of FIGURE 2, whereby the drive gear makes nearly onethird of a revolution to impart one counting step equivalent to one-tenth of a revolution to the units wheel 10A, which step will be completed upon return of the pawl to the centralized or neutral position aforesaid, the relative spacing of the offset pawl teeth in each set being such that when the pawl returns to the central position after advancing the drive gear 26 almost, but not quite, a complete step as aforesaid, another one of the trident teeth thereof on the opposite side of the axis of shaft 13 will be slightly and transiently pushed on return of the pawl to central position to complete such advancing step and cause the appropriate number on the wheel to be properly centered in the window 19. This kind of action occurs identically whether the pawl moves to the right or the left of its central position, the direction of movement of the pawl from such position simply determining Whether the counting wheels move additively or subtractively, that is, clockwise or counterclockwise, FIGURES 2, 2A.

The foregoing action of the tri-dent gear 26 when displaced by some form of stepping pawl is known in the art, but the special configuration of the pawl in effecting the reverse movements of gear 26 is novel. Moreover, while the counting wheels 10, in general, and their cumulative counting advance responsive to stepping 0f a tri-dent drive gear 26, in general, constitute known art, the counting wheels herein disclosed are modified to provide means for signalling a zero-count or starting condition, while permitting the individual wheels to continue through revolution after revolution, such means including a control ring 30 on each of the counting wheels, FIGURES 1 to 3, the radial depth of each such ring being uniform about its circumference except for a zeronotch 31 in each such ring, the depth of such notch being such that a rockable zero-sensitive plate 38 pivoted on pin 39, FIGURES 2 and 3, will drop into the aligned series of control ring notches 31 when all of the appertaining number wheels are at zero or starting position.

As seen in FIGURES 2 and 3, the signalling means includes a small snap-switch 40 having an actuating lever 41 pivoted thereon and projecting beneath an extension piece or wing 42 welded on the zero rocker plate such that when the latter is rocked upwardly or counterclockwise, as viewed in FIGURE 2, the eccentric wing portion 42 thereof will bear down upon the switch lever 41 and actuate said switch to signal the off-zero condition of the counter. A single step of the first or units wheel will actuate the switch and the control rings of the successive wheels will maintain this condition while the lower-value wheels rotate continuously until the count is reached or the zero condition restored.

The control switch 40 is mounted on an inwardlyturned llange portion 16F of the casing wall 16, while the complementary casing has a corner portion 17D, FIG- URES 4, 5, 7 and 8, cut out to expose two sides (those of FIGURES 2 and 3) to view in the assembled condition of the two subassembly chassis or casing sections.

Means for driving the pawl 20 reversely comprises a pair of electromagnets 48 and 49 and an armature 50, FIGURES 5, 6, 7, carried by the casing subassembly 17.

On oppositely-facing casing walls 17A, 17B are identically aligned inwardly struck bosses 57 each pitched to alord an angular seat for one of said electromagnets such that when the armature 50 is attracted by either, as in FIGURE 5, the plane of the armature and the plane of the magnet pole face will be substantially parallel to atord maximum armature displacement and magnetic eiciency, and to reduce chattering in the case of alternating current coils having the phase-splitting slugs on the pole face for this purpose.

The armature 50 has a pair of closely-spaced lugs 51, FIGURES 6, 7 and 9, which seat rockably in corresponding punches in the back wall 17C of the subassembly casing member, and the confronting edges of the lugs have aligned slots 52, FIGURE 9, exposed at the outer surface of the casing wall to receive (FIGURE 7) a bowed ilat retaining spring 54 which holds the armature in assembly with the casing Wall while permitting springbuttered movement of the lugs for the full arcuate swing of the armature, the opposite end of which has a reduced tongue 55, FIGURES 6, 8, 9, fitting freely but closely into the hour-glass coupling slot 23 in the manner shown particularly in FIGURES 8 and 9, so that when the armature is attracted by one or the other of the two electromagnets from a central idle position corresponding to the centralized idle position of the oscillable pawl 20, the latter will be rocked correspondingly to effect a clockwise or counterclockwise movement of the pawl and an additive or subtractive stepping of the units wheel 4 10A, as previously explained. The reduced tongue 5S on the armature is exposed, FIGURE 8, through a hole 14A in the wall of the wheel chassis for manual enagement to actuate the counter additively or subtractively.

The armature 50 and coupled pawl 20 are returned and maintained in the central idle position by a spring rocker means comprising a wide rocker plate 60, FIGURES 5, 6 and 9, having spaced rocker lugs 61, FIGURES 6, 9, rockably seating in matching slots 62 in casing wall 17C; another pair of wider endwise lugs 63 at the opposite end of the rocker plate, FIGURES 5, 6 and 9, are spaced and disposed to underlie and press upon shoulders 20X, FIGURES 2, 2A, and 9, of the oscillable pawl on opposite sides of the pivotal axis and mounting 21 thereof.

As seen in FIGURES 5, 6 and 9, the neutralizing presser plate 60 has a lengthwise slot 65 punched therein at one end of which is a spring lug 66 upon which is anchored one end of a traction spring 67, the opposite end of which is anchored on lug means 68 in the casing wall, FIGURE 7, in a position such that the rocker plate is constantly biased upwardly to thrust its two lugs 63 against the shoulders 20X on pawl 20 with the result that the latter is yieldingly held and forced to return to its centralized idle position when free to do so.

The spring 67 is of a diameter, and is so disposed rela.- tive to the slot 65, FIGURE 6, as to expose a large number of its coils to engagement by the confronting edge of the armature 50 in the centralized mid-position of the latter, in consequence of which the spring exerts a moderate pressure etiect responsive to energization of either of the electromagnets. This action eliects positive displacements of the armature in moving oli-center and tends to aid reduction of chatter in A.C. operation. While the pawlcentering presser plate 60 exerts sucient force always to return the armature (through the pawl) to normal midposition when the electromagnet is deenergized, the additional pressure of the spring coils against the edge of the armature in mid-position effects a moderate snap-action Off center and assists in stabilizing the maintenance of the centralized position of the armature and the pawl, slight movements of which off-center can cause the units counter wheel 10A to move more or less out of proper register and reading position relative to the sight opening or window 19.

As a result, the foregoing configuration and action of the driving pawl 20, the armature means 50, pitched mounting 57 of the electromagnets, 4and the positive centering and snap-throw action of the spring presser plate means 60, 65, 67, effects consistently accurate and rapid reverse stepping of the counting wheels with moderate driving power in a subassembly construction which is economical to assemble and readily disassembled for servicing as by replacement of the coils or the switch or for the purpose of adjusting the sensitivity of the switch in respect to the slight off-zero signalling movements of the zero-sensing rocker bar 38. A small window 70, FIGURE 8, adjacent the switch 40 affords access to an adjusting screw 40X on the switch, which usually suffices for initial alignment.

The two subassembly chassis interfit, as in FIGURE 8, the opposite sidewalls 17A, 17B of one being joined by a tie rod 74, FIGURES 6 and 8, having a groove and head formation 7S at opposite ends, FIGURES 4 and 8, which snap into edgewise slots 17S, in the opposite chassis walls 17A, 17B, this tie rod also engaging in another pair of aligned slots 14S, FIGURE 1, formed in a pair of wings offset from wall 14 of the wheel chassis. If desired, a bottom closure plate (not illustrated) may be added, for which purpose sidewall screw holes 74, FIGURES 4 and 8, are provided.

For rapid counting in small counters measuring perhaps 2 x 2 x 3 inches, the drive pawls must be as small and light as possible; and for continuous duty they must have maximum strength.

These requirements are met by the constructions shown about the tri-dent drive gear 26 and very close to the units wheel A.

Another advantage of the pawl structure also deriving from the arcuate slot and its salient teeth resides in the fact that such an arrangement makes it possible to minimize the amplitude of the right or left swing of the armature to achieve the required advance of the units wheel in a given available space which is inherently confining.

Another feature of the construction of pawl is the provision of centering thrust shoulders 20X on opposite sides of its pivotal axis and the coaction thereof with opposite presser lugs 63 on the centering plate 60.

The several advantages of the pawl configuration in strength in minimal mass and displacement, may be availed of in the uni-directional or non-resetting or nonsubtracting type of counter, for which purposes the modified pawl 80 depicted in FIGURE 2B also employs -a closed arcuate opening 81, which on comparison with the reverse-driving pawl of FIGURE 2A, will be seen to constitute approximately one-half of the symmetrical configuration of the pawl 20 on opposite sides of a vertical center line through the pivotal axis and the hour-glass shaped coupling notch.

Thus, the uni-directional pawl 80 has only one pair of salient teeth 82, 83, both located at one side of aline connecting the center of the shaft 84 for a tri-dent gear 85, the coupling notch 86 and the pivot 87, which line defines the neutral or starting position for this pawl, each oscillatory excursion from and back to this position effecting one fractional revolution of the gear 85 and the associated counting Wheels (not shown but operatively identical to wheels 10) the lower salient pawl tooth 83 first starting the gear on the outbound (clockwise) stroke, and the upper tooth 82 completing the advance of the gear on return to the starting position.

The unidirectional pawl 80 has a reinforcing arch 88 similar to the longer arch 22 of the pawl 120.

I claim:

1. In a counting mechanism of the type having a set of number wheels moved from a normal zero starting position in counting action by a trident gear revolved by an `oscillatory pawl, the combination with said gear of a pivoted pawl for driving the same one revolution per oscillation of the pawl; an armature mounted at one end thereof for oscillation With respect to a normal central position; and drivingly engaging said pawl at an opposite end thereof; spring-urged means acting on said pawl to dispose the same in a corresponding normal central position; electromagnetic means for oscillating the armature to and from said central position; spring means engaging the armature at one side thereof in a normal central position of the armature to impart thereto a form of snap action in moving from said central position to terminal positions outward therefrom; said pawl having formed therein an opening for the trident gear remote from the pivotal axis of the pawl and extending in an arcuate sense concentrically of said axis, and further means formed on opposite sides of said opening and lying on opposite sides of a radius of said axis and located on opposite sides of said radius defining opposite gear teeth cooperable with said trident gear to advance the latter one revolution for each excursion of the pawl from and back to said central position responsive to actuation of said electromagnetic means; together with off-zero control means comprising a movable control member engaging peripheral means on each number wheel and positioned thereby in a first control condition when the wheels are all in zero starting position, and positioned thereby in a second control condition so long as at least one of said wheels is in off-zero position.

2. Apparatus according to claim 1 wherein said pawl is in the form of a fiat plate and said opening therein is arcuate and lies wholly within the body of the plate and `affords a reinforcing arch constituting one angular side of the opening, said trident gear fitting within said opening.

3. The construction of claim 2 wherein said further means defining gear teeth comprises a salient tooth portion projecting inwardly in a radial sense of the arc toward the pivotal axis of the pawl and located on one side of said radius, and another salient tooth portion projecting outwardly in a radial sense but on the opposite side of said radius and on the near side of the arc toward said axis.

4. A construction according to claim 2 wherein said further means defining gear teeth comprises a salient tooth located centrally of said arc on the radially far side thereof from said axis and on said radius, and said tooth has opposite sides each located on a side of said radius opposite from the other and each constituting a gear-engaging margin drivingly engageable with the trident gear, the near side of the arc proximate to the pivotal axis of the pawl having a centrally located notch on said radius and inwardly toward said axis with opposite marginal portions at opposite ends thereof each constituting a gearengaging portion also respectively drivingly cooperable with said trident gear such that the pawl in oscillatory excursions from and back to said central position thereof can rotate the trident gear correspondingly through the action of a pair of said gear-engaging portions each pair disposed on opposite sides of the arcuate opening on one or the other side of said radius.

5. Mechanism according to claim 1 wherein said offzero control means comprises a ring means projecting radially beyond the periphery of each number wheel circumarnbiently thereof and each said ring means is provided with a detent means disposed relative to the zero position of the appertaining wheel, and said control member comprises an elongated member rockably mounted adjacent said wheels and urged against the said ring means thereof for engagement with the said detent means thereof such that when all wheels lare in the zero starting position said member will rock into the first said condition, and when any wheel is off-zero the said control member will thereby be rocked and maintained in the second condition by peripheral portions of the appertaining ring means moved relative to said control member by displacement of such wheel from zero position.

6. Mechanism yaccording to claim 1 wherein said pawl is in the form of a flat plate member and said opening is of elongated arcuate character concentric with the pivotal axis of the pawl, and said plate has formed thereon a pair of shoulders each situated adjacent to and respectively on a side of said axis opposite from the other, and said presser means comprises a rockable plate mounted at one end and having spaced apart projection-sat an opposite end thereof and each pressed against one of said shoulders by action of said spring means to move the pawl yieldingly into the central position aforesaid.

7. Counting mechanism as set forth in claim 1 wherein said mechanism is mounted on a chassis member having opposite wall portions each confronting an opposite side of said armature, and said electromagnetic means cornprises a pair of electromagnets each mounted on one of said wall portions to confront a side of the armature opposite from the side confronted by the other, and each said wall portion is provided with a boss projecting toward Ithe appertaining side of the armature and each said boss affords an angularly pitched seat for one of said electromagnets disposing a pole face thereof in angular relation to the juxtaposed side of the armature to procure a predetermined magnetic relation with the armature.

8. Counting mechanism according to claim l'wherein said spring-urged means acting on said pawl comprises an elongated plate means rockably mounted at one end and 7 having pawl-engaging portions engaging the pawl on diametrically opposite sides of the pivotal axis of the pawl with spring means acting on said plate to cause the same to apply equal forces to the pawl on opposite sides of said axis whereby to urge the pawl into said central position.

9. Mechanism according to claim 8 wherein the said spring means acting on the plate is the same spring means engaging the armature to impart snap action as aforesaid.

10. Mechanism according to claim 9' wherein said plate has a long slot therein, said spring means acting thereon is an elongated coil spring having coil portions exposed References Cited UNITED STATES PATENTS 522,113 6/1894 Glass 23S-92 1,121,634 12/19'14 Julian 74--159 STEPHEN J. TOMSKY, Primary Examiner. 

1. IN A COUNTING MECHANISM OF THE TYPE HAVING A SET OF NUMBER WHEELS MOVED FROM A NORMAL ZERO STARTING POSITION IN COUNTING ACTION BY A TRIDENT GEAR REVOLVED BY AN OSCILLATORY PAWL, THE COMBINATION WITH SAID GEAR OF A PIVOTED PAWL FOR DRIVING THE SAME ONE REVOLUTION PER OSCILLATION OF THE PAWL; AN ARMATURE MOUNTED AT ONE END THEREOF FOR OSCILLATION WITH RESPECT TO A NORMAL CENTRAL POSITION; AND DRIVINGLY ENGAGING SAID PAWL AT AN OPPOSITE END THEREOF; SPRING-URGED MEANS ACTING ON SAID PAWL TO DISPOSE THE SAME IN A CORRESPONDING NORMAL CENTRAL POSITION; ELECTROMAGNETIC MEANS FOR OSCILLATING THE ARMATURE TO AND FROM SAID CENTRAL POSITION; SPRING MEANS ENGAGING THE ARMATURE AT ONE SIDE THEREOF IN A NORMAL CENTRAL POSITION OF THE ARMATURE TO IMPART THERETO A FORM OF SNAP ACTION IN MOVING FROM SAID CENTRAL POSITION TO TERMINAL POSITIONS OUTWARD THEREFROM; SAID PAWL HAVING FORMED THEREIN AN OPENING FOR THE TRIDENT GEAR REMOTE FROM THE PIVOTAL AXIS OF THE PAWL AND EXTENDING IN AN ARCUATE SENSE CONCENTRICALLY OF SAID AXIS, AND FURTHER MEANS FORMED ON OPPOSITE SIDES OF SAID OPENING AND LYING ON OPPOSITE SIDES OF A RADIUS OF SAID AXIS AND LOCATED ON OPPOSITE SIDES OF SAID RADIUS DEFINING OPPOSITE GEAR TEETH COOPERABLE WITH SAID TRIDENT GEAR TO ADVANCE THE LATTER ONE REVOLUTION FOR EACH EXCURSION OF THE PAWL FROM AND BACK TO SAID CENTRAL POSITION RESPONSIVE TO ACTUATION OF SAID ELECTROMAGNETIC MEANS; TOGETHER WITH OFF-ZERO CONTROL MEANS COMPRISING A MOVABLE CONTROL MEMBER ENGAGING PERIPHERAL MEANS ON EACH NUMBER WHEEL AND POSITIONED THEREBY IN A FIRST CONTROL CONDITION WHEN THE WHEELS ARE ALL IN ZERO STARTING POSITION, AND POSITIONED THEREBY IN A SECOND CONTROL CONDITION SO LONG AS AT LEAST ONE OF SAID WHEELS IS IN OFF-ZERO POSITION. 